1. Technical Field
The present invention relates to an electronic endoscopic device.
2. Related Art
An electronic endoscopic system which is used in a medical field is configured by an electronic endoscope (scope) and a processor device. The electronic endoscope includes an imaging device including a solid-state imaging element at a tip end of an insertion unit which is inserted into a subject. The processor device controls an operation of the imaging device and performs various signal processings on an imaging signal which is output from the imaging device to display an endoscopic image on a monitor (a display device).
The temperature inside the tip end of the endoscope insertion unit easily rises due to, for example, heat generation of the solid-state imaging element (a CCD sensor or a CMOS sensor) or heat generation from lost light quantity of a light guide. When an internal temperature of the endoscope insertion unit rises, a noise of an image signal is increased and an image quality is degraded. Further, when a temperature of the tip end of the endoscope insertion unit exceeds a reference temperature, a safety problem may be caused. Therefore, it is demanded to take preventive measures to detect a temperature of the endoscope insertion unit to control the temperature or issue a warning to an operator of the endoscope when the temperature rises.
Patent Literature 1 (JP-A-2013-000466) discloses a configuration which includes a temperature detecting unit at a tip end of an endoscope insertion unit so that when the detected temperature of the tip end becomes high, a frame rate is decreased and a light quantity is reduced to suppress heat generation.
Patent Literature 2 (JP-A-2012-143319) discloses a configuration which includes a temperature detecting unit at a tip end of an endoscope insertion unit so that when the detected temperature of the tip end becomes high, a frame rate is decreased to suppress heat generation.
Patent Literature 3 (JP-A-2012-081001) discloses an electronic endoscope which decreases a frame rate to reduce heat generation when a light quantity radiated from the light source exceeds a limit light quantity.